hw/qdev.h

   1 #ifndef QDEV_H
   2 #define QDEV_H
   3
   4 #include "hw.h"
   5 #include "qemu-queue.h"
   6 #include "qemu-char.h"
   7 #include "qemu-option.h"
   8 #include "qapi/qapi-visit-core.h"
   9 #include "qemu/object.h"
  10
  11 typedef struct Property Property;
  12
  13 typedef struct PropertyInfo PropertyInfo;
  14
  15 typedef struct CompatProperty CompatProperty;
  16
  17 typedef struct DeviceInfo DeviceInfo;
  18
  19 typedef struct BusState BusState;
  20
  21 typedef struct BusInfo BusInfo;
  22
  23 enum DevState {
  24     DEV_STATE_CREATED = 1,
  25     DEV_STATE_INITIALIZED,
  26 };
  27
  28 enum {
  29     DEV_NVECTORS_UNSPECIFIED = -1,
  30 };
  31
  32 /**
  33  * @DevicePropertyAccessor - called when trying to get/set a property
  34  *
  35  * @dev the device that owns the property
  36  * @v the visitor that contains the property data
  37  * @opaque the device property opaque
  38  * @name the name of the property
  39  * @errp a pointer to an Error that is filled if getting/setting fails.
  40  */
  41 typedef void (DevicePropertyAccessor)(DeviceState *dev,
  42                                       Visitor *v,
  43                                       void *opaque,
  44                                       const char *name,
  45                                       Error **errp);
  46
  47 /**
  48  * @DevicePropertyRelease - called when a property is removed from a device
  49  *
  50  * @dev the device that owns the property
  51  * @name the name of the property
  52  * @opaque the opaque registered with the property
  53  */
  54 typedef void (DevicePropertyRelease)(DeviceState *dev,
  55                                      const char *name,
  56                                      void *opaque);
  57
  58 typedef struct DeviceProperty
  59 {
  60     gchar *name;
  61     gchar *type;
  62     DevicePropertyAccessor *get;
  63     DevicePropertyAccessor *set;
  64     DevicePropertyRelease *release;
  65     void *opaque;
  66
  67     QTAILQ_ENTRY(DeviceProperty) node;
  68 } DeviceProperty;
  69
  70 #define TYPE_DEVICE "device"
  71 #define DEVICE(obj) OBJECT_CHECK(DeviceState, (obj), TYPE_DEVICE)
  72 #define DEVICE_CLASS(klass) OBJECT_CLASS_CHECK(DeviceClass, (klass), TYPE_DEVICE)
  73 #define DEVICE_GET_CLASS(obj) OBJECT_GET_CLASS(DeviceClass, (obj), TYPE_DEVICE)
  74
  75 typedef struct DeviceClass {
  76     ObjectClass parent_class;
  77     DeviceInfo *info;
  78     void (*reset)(DeviceState *dev);
  79 } DeviceClass;
  80
  81 /* This structure should not be accessed directly.  We declare it here
  82    so that it can be embedded in individual device state structures.  */
  83 struct DeviceState {
  84     Object parent_obj;
  85
  86     const char *id;
  87     enum DevState state;
  88     QemuOpts *opts;
  89     int hotplugged;
  90     BusState *parent_bus;
  91     int num_gpio_out;
  92     qemu_irq *gpio_out;
  93     int num_gpio_in;
  94     qemu_irq *gpio_in;
  95     QLIST_HEAD(, BusState) child_bus;
  96     int num_child_bus;
  97     QTAILQ_ENTRY(DeviceState) sibling;
  98     int instance_id_alias;
  99     int alias_required_for_version;
 100
 101     /**
 102      * This tracks the number of references between devices.  See @qdev_ref for
 103      * more information.
 104      */
 105     uint32_t ref;
 106
 107     QTAILQ_HEAD(, DeviceProperty) properties;
 108
 109     /* Do not, under any circumstance, use this parent link below anywhere
 110      * outside of qdev.c.  You have been warned. */
 111     DeviceState *parent;
 112 };
 113
 114 typedef void (*bus_dev_printfn)(Monitor *mon, DeviceState *dev, int indent);
 115 typedef char *(*bus_get_dev_path)(DeviceState *dev);
 116 /*
 117  * This callback is used to create Open Firmware device path in accordance with
 118  * OF spec http://forthworks.com/standards/of1275.pdf. Indicidual bus bindings
 119  * can be found here http://playground.sun.com/1275/bindings/.
 120  */
 121 typedef char *(*bus_get_fw_dev_path)(DeviceState *dev);
 122 typedef int (qbus_resetfn)(BusState *bus);
 123
 124 struct BusInfo {
 125     const char *name;
 126     size_t size;
 127     bus_dev_printfn print_dev;
 128     bus_get_dev_path get_dev_path;
 129     bus_get_fw_dev_path get_fw_dev_path;
 130     qbus_resetfn *reset;
 131     Property *props;
 132 };
 133
 134 struct BusState {
 135     DeviceState *parent;
 136     BusInfo *info;
 137     const char *name;
 138     int allow_hotplug;
 139     int qdev_allocated;
 140     QTAILQ_HEAD(ChildrenHead, DeviceState) children;
 141     QLIST_ENTRY(BusState) sibling;
 142 };
 143
 144 struct Property {
 145     const char   *name;
 146     PropertyInfo *info;
 147     int          offset;
 148     int          bitnr;
 149     void         *defval;
 150 };
 151
 152 enum PropertyType {
 153     PROP_TYPE_UNSPEC = 0,
 154     PROP_TYPE_UINT8,
 155     PROP_TYPE_UINT16,
 156     PROP_TYPE_UINT32,
 157     PROP_TYPE_INT32,
 158     PROP_TYPE_UINT64,
 159     PROP_TYPE_TADDR,
 160     PROP_TYPE_MACADDR,
 161     PROP_TYPE_LOSTTICKPOLICY,
 162     PROP_TYPE_DRIVE,
 163     PROP_TYPE_CHR,
 164     PROP_TYPE_STRING,
 165     PROP_TYPE_NETDEV,
 166     PROP_TYPE_VLAN,
 167     PROP_TYPE_PTR,
 168     PROP_TYPE_BIT,
 169 };
 170
 171 struct PropertyInfo {
 172     const char *name;
 173     const char *legacy_name;
 174     size_t size;
 175     enum PropertyType type;
 176     int64_t min;
 177     int64_t max;
 178     int (*parse)(DeviceState *dev, Property *prop, const char *str);
 179     int (*print)(DeviceState *dev, Property *prop, char *dest, size_t len);
 180     void (*free)(DeviceState *dev, Property *prop);
 181     DevicePropertyAccessor *get;
 182     DevicePropertyAccessor *set;
 183 };
 184
 185 typedef struct GlobalProperty {
 186     const char *driver;
 187     const char *property;
 188     const char *value;
 189     QTAILQ_ENTRY(GlobalProperty) next;
 190 } GlobalProperty;
 191
 192 /*** Board API.  This should go away once we have a machine config file.  ***/
 193
 194 DeviceState *qdev_create(BusState *bus, const char *name);
 195 DeviceState *qdev_try_create(BusState *bus, const char *name);
 196 bool qdev_exists(const char *name);
 197 int qdev_device_help(QemuOpts *opts);
 198 DeviceState *qdev_device_add(QemuOpts *opts);
 199 int qdev_init(DeviceState *dev) QEMU_WARN_UNUSED_RESULT;
 200 void qdev_init_nofail(DeviceState *dev);
 201 void qdev_set_legacy_instance_id(DeviceState *dev, int alias_id,
 202                                  int required_for_version);
 203 int qdev_unplug(DeviceState *dev);
 204 void qdev_free(DeviceState *dev);
 205 int qdev_simple_unplug_cb(DeviceState *dev);
 206 void qdev_machine_creation_done(void);
 207 bool qdev_machine_modified(void);
 208
 209 qemu_irq qdev_get_gpio_in(DeviceState *dev, int n);
 210 void qdev_connect_gpio_out(DeviceState *dev, int n, qemu_irq pin);
 211
 212 BusState *qdev_get_child_bus(DeviceState *dev, const char *name);
 213
 214 /*** Device API.  ***/
 215
 216 typedef int (*qdev_initfn)(DeviceState *dev, DeviceInfo *info);
 217 typedef int (*qdev_event)(DeviceState *dev);
 218 typedef void (*qdev_resetfn)(DeviceState *dev);
 219
 220 struct DeviceInfo {
 221     const char *name;
 222     const char *fw_name;
 223     const char *alias;
 224     const char *desc;
 225     size_t size;
 226     Property *props;
 227     int no_user;
 228
 229     /* callbacks */
 230     qdev_resetfn reset;
 231
 232     /* device state */
 233     const VMStateDescription *vmsd;
 234
 235     /**
 236      * See #TypeInfo::class_init()
 237      */
 238     void (*class_init)(ObjectClass *klass, void *data);
 239
 240     /* Private to qdev / bus.  */
 241     qdev_initfn init;
 242     qdev_event unplug;
 243     qdev_event exit;
 244     BusInfo *bus_info;
 245     struct DeviceInfo *next;
 246 };
 247 extern DeviceInfo *device_info_list;
 248
 249 void qdev_register(DeviceInfo *info);
 250 void qdev_register_subclass(DeviceInfo *info, const char *parent);
 251
 252 /* Register device properties.  */
 253 /* GPIO inputs also double as IRQ sinks.  */
 254 void qdev_init_gpio_in(DeviceState *dev, qemu_irq_handler handler, int n);
 255 void qdev_init_gpio_out(DeviceState *dev, qemu_irq *pins, int n);
 256
 257 CharDriverState *qdev_init_chardev(DeviceState *dev);
 258
 259 BusState *qdev_get_parent_bus(DeviceState *dev);
 260
 261 /*** BUS API. ***/
 262
 263 DeviceState *qdev_find_recursive(BusState *bus, const char *id);
 264
 265 /* Returns 0 to walk children, > 0 to skip walk, < 0 to terminate walk. */
 266 typedef int (qbus_walkerfn)(BusState *bus, void *opaque);
 267 typedef int (qdev_walkerfn)(DeviceState *dev, void *opaque);
 268
 269 void qbus_create_inplace(BusState *bus, BusInfo *info,
 270                          DeviceState *parent, const char *name);
 271 BusState *qbus_create(BusInfo *info, DeviceState *parent, const char *name);
 272 /* Returns > 0 if either devfn or busfn skip walk somewhere in cursion,
 273  *         < 0 if either devfn or busfn terminate walk somewhere in cursion,
 274  *           0 otherwise. */
 275 int qbus_walk_children(BusState *bus, qdev_walkerfn *devfn,
 276                        qbus_walkerfn *busfn, void *opaque);
 277 int qdev_walk_children(DeviceState *dev, qdev_walkerfn *devfn,
 278                        qbus_walkerfn *busfn, void *opaque);
 279 void qdev_reset_all(DeviceState *dev);
 280 void qbus_reset_all_fn(void *opaque);
 281
 282 void qbus_free(BusState *bus);
 283
 284 #define FROM_QBUS(type, dev) DO_UPCAST(type, qbus, dev)
 285
 286 /* This should go away once we get rid of the NULL bus hack */
 287 BusState *sysbus_get_default(void);
 288
 289 /*** monitor commands ***/
 290
 291 void do_info_qtree(Monitor *mon);
 292 void do_info_qdm(Monitor *mon);
 293 int do_device_add(Monitor *mon, const QDict *qdict, QObject **ret_data);
 294 int do_device_del(Monitor *mon, const QDict *qdict, QObject **ret_data);
 295
 296 /*** qdev-properties.c ***/
 297
 298 extern PropertyInfo qdev_prop_bit;
 299 extern PropertyInfo qdev_prop_uint8;
 300 extern PropertyInfo qdev_prop_uint16;
 301 extern PropertyInfo qdev_prop_uint32;
 302 extern PropertyInfo qdev_prop_int32;
 303 extern PropertyInfo qdev_prop_uint64;
 304 extern PropertyInfo qdev_prop_hex8;
 305 extern PropertyInfo qdev_prop_hex32;
 306 extern PropertyInfo qdev_prop_hex64;
 307 extern PropertyInfo qdev_prop_string;
 308 extern PropertyInfo qdev_prop_chr;
 309 extern PropertyInfo qdev_prop_ptr;
 310 extern PropertyInfo qdev_prop_macaddr;
 311 extern PropertyInfo qdev_prop_losttickpolicy;
 312 extern PropertyInfo qdev_prop_drive;
 313 extern PropertyInfo qdev_prop_netdev;
 314 extern PropertyInfo qdev_prop_vlan;
 315 extern PropertyInfo qdev_prop_pci_devfn;
 316
 317 #define DEFINE_PROP(_name, _state, _field, _prop, _type) { \
 318         .name      = (_name),                                    \
 319         .info      = &(_prop),                                   \
 320         .offset    = offsetof(_state, _field)                    \
 321             + type_check(_type,typeof_field(_state, _field)),    \
 322         }
 323 #define DEFINE_PROP_DEFAULT(_name, _state, _field, _defval, _prop, _type) { \
 324         .name      = (_name),                                           \
 325         .info      = &(_prop),                                          \
 326         .offset    = offsetof(_state, _field)                           \
 327             + type_check(_type,typeof_field(_state, _field)),           \
 328         .defval    = (_type[]) { _defval },                             \
 329         }
 330 #define DEFINE_PROP_BIT(_name, _state, _field, _bit, _defval) {  \
 331         .name      = (_name),                                    \
 332         .info      = &(qdev_prop_bit),                           \
 333         .bitnr    = (_bit),                                      \
 334         .offset    = offsetof(_state, _field)                    \
 335             + type_check(uint32_t,typeof_field(_state, _field)), \
 336         .defval    = (bool[]) { (_defval) },                     \
 337         }
 338
 339 #define DEFINE_PROP_UINT8(_n, _s, _f, _d)                       \
 340     DEFINE_PROP_DEFAULT(_n, _s, _f, _d, qdev_prop_uint8, uint8_t)
 341 #define DEFINE_PROP_UINT16(_n, _s, _f, _d)                      \
 342     DEFINE_PROP_DEFAULT(_n, _s, _f, _d, qdev_prop_uint16, uint16_t)
 343 #define DEFINE_PROP_UINT32(_n, _s, _f, _d)                      \
 344     DEFINE_PROP_DEFAULT(_n, _s, _f, _d, qdev_prop_uint32, uint32_t)
 345 #define DEFINE_PROP_INT32(_n, _s, _f, _d)                      \
 346     DEFINE_PROP_DEFAULT(_n, _s, _f, _d, qdev_prop_int32, int32_t)
 347 #define DEFINE_PROP_UINT64(_n, _s, _f, _d)                      \
 348     DEFINE_PROP_DEFAULT(_n, _s, _f, _d, qdev_prop_uint64, uint64_t)
 349 #define DEFINE_PROP_HEX8(_n, _s, _f, _d)                       \
 350     DEFINE_PROP_DEFAULT(_n, _s, _f, _d, qdev_prop_hex8, uint8_t)
 351 #define DEFINE_PROP_HEX32(_n, _s, _f, _d)                       \
 352     DEFINE_PROP_DEFAULT(_n, _s, _f, _d, qdev_prop_hex32, uint32_t)
 353 #define DEFINE_PROP_HEX64(_n, _s, _f, _d)                       \
 354     DEFINE_PROP_DEFAULT(_n, _s, _f, _d, qdev_prop_hex64, uint64_t)
 355 #define DEFINE_PROP_PCI_DEVFN(_n, _s, _f, _d)                   \
 356     DEFINE_PROP_DEFAULT(_n, _s, _f, _d, qdev_prop_pci_devfn, uint32_t)
 357
 358 #define DEFINE_PROP_PTR(_n, _s, _f)             \
 359     DEFINE_PROP(_n, _s, _f, qdev_prop_ptr, void*)
 360 #define DEFINE_PROP_CHR(_n, _s, _f)             \
 361     DEFINE_PROP(_n, _s, _f, qdev_prop_chr, CharDriverState*)
 362 #define DEFINE_PROP_STRING(_n, _s, _f)             \
 363     DEFINE_PROP(_n, _s, _f, qdev_prop_string, char*)
 364 #define DEFINE_PROP_NETDEV(_n, _s, _f)             \
 365     DEFINE_PROP(_n, _s, _f, qdev_prop_netdev, VLANClientState*)
 366 #define DEFINE_PROP_VLAN(_n, _s, _f)             \
 367     DEFINE_PROP(_n, _s, _f, qdev_prop_vlan, VLANState*)
 368 #define DEFINE_PROP_DRIVE(_n, _s, _f) \
 369     DEFINE_PROP(_n, _s, _f, qdev_prop_drive, BlockDriverState *)
 370 #define DEFINE_PROP_MACADDR(_n, _s, _f)         \
 371     DEFINE_PROP(_n, _s, _f, qdev_prop_macaddr, MACAddr)
 372 #define DEFINE_PROP_LOSTTICKPOLICY(_n, _s, _f, _d) \
 373     DEFINE_PROP_DEFAULT(_n, _s, _f, _d, qdev_prop_losttickpolicy, \
 374                         LostTickPolicy)
 375
 376 #define DEFINE_PROP_END_OF_LIST()               \
 377     {}
 378
 379 /* Set properties between creation and init.  */
 380 void *qdev_get_prop_ptr(DeviceState *dev, Property *prop);
 381 int qdev_prop_exists(DeviceState *dev, const char *name);
 382 int qdev_prop_parse(DeviceState *dev, const char *name, const char *value);
 383 void qdev_prop_set(DeviceState *dev, const char *name, void *src, enum PropertyType type);
 384 void qdev_prop_set_bit(DeviceState *dev, const char *name, bool value);
 385 void qdev_prop_set_uint8(DeviceState *dev, const char *name, uint8_t value);
 386 void qdev_prop_set_uint16(DeviceState *dev, const char *name, uint16_t value);
 387 void qdev_prop_set_uint32(DeviceState *dev, const char *name, uint32_t value);
 388 void qdev_prop_set_int32(DeviceState *dev, const char *name, int32_t value);
 389 void qdev_prop_set_uint64(DeviceState *dev, const char *name, uint64_t value);
 390 void qdev_prop_set_string(DeviceState *dev, const char *name, char *value);
 391 void qdev_prop_set_chr(DeviceState *dev, const char *name, CharDriverState *value);
 392 void qdev_prop_set_netdev(DeviceState *dev, const char *name, VLANClientState *value);
 393 void qdev_prop_set_vlan(DeviceState *dev, const char *name, VLANState *value);
 394 int qdev_prop_set_drive(DeviceState *dev, const char *name, BlockDriverState *value) QEMU_WARN_UNUSED_RESULT;
 395 void qdev_prop_set_drive_nofail(DeviceState *dev, const char *name, BlockDriverState *value);
 396 void qdev_prop_set_macaddr(DeviceState *dev, const char *name, uint8_t *value);
 397 void qdev_prop_set_losttickpolicy(DeviceState *dev, const char *name,
 398                                   LostTickPolicy *value);
 399 /* FIXME: Remove opaque pointer properties.  */
 400 void qdev_prop_set_ptr(DeviceState *dev, const char *name, void *value);
 401 void qdev_prop_set_defaults(DeviceState *dev, Property *props);
 402
 403 void qdev_prop_register_global_list(GlobalProperty *props);
 404 void qdev_prop_set_globals(DeviceState *dev);
 405 void error_set_from_qdev_prop_error(Error **errp, int ret, DeviceState *dev,
 406                                     Property *prop, const char *value);
 407
 408 DeviceInfo *qdev_get_info(DeviceState *dev);
 409
 410 static inline const char *qdev_fw_name(DeviceState *dev)
 411 {
 412     DeviceInfo *info = qdev_get_info(dev);
 413
 414     if (info->fw_name) {
 415         return info->fw_name;
 416     } else if (info->alias) {
 417         return info->alias;
 418     }
 419
 420     return object_get_typename(OBJECT(dev));
 421 }
 422
 423 char *qdev_get_fw_dev_path(DeviceState *dev);
 424 /* This is a nasty hack to allow passing a NULL bus to qdev_create.  */
 425 extern struct BusInfo system_bus_info;
 426
 427 /**
 428  * @qdev_ref
 429  *
 430  * Increase the reference count of a device.  A device cannot be freed as long
 431  * as its reference count is greater than zero.
 432  *
 433  * @dev - the device
 434  */
 435 void qdev_ref(DeviceState *dev);
 436
 437 /**
 438  * @qdef_unref
 439  *
 440  * Decrease the reference count of a device.  A device cannot be freed as long
 441  * as its reference count is greater than zero.
 442  *
 443  * @dev - the device
 444  */
 445 void qdev_unref(DeviceState *dev);
 446
 447 /**
 448  * @qdev_property_add - add a new property to a device
 449  *
 450  * @dev - the device to add a property to
 451  *
 452  * @name - the name of the property.  This can contain any character except for
 453  *         a forward slash.  In general, you should use hyphens '-' instead of
 454  *         underscores '_' when naming properties.
 455  *
 456  * @type - the type name of the property.  This namespace is pretty loosely
 457  *         defined.  Sub namespaces are constructed by using a prefix and then
 458  *         to angle brackets.  For instance, the type 'virtio-net-pci' in the
 459  *         'link' namespace would be 'link<virtio-net-pci>'.
 460  *
 461  * @get - the getter to be called to read a property.  If this is NULL, then
 462  *        the property cannot be read.
 463  *
 464  * @set - the setter to be called to write a property.  If this is NULL,
 465  *        then the property cannot be written.
 466  *
 467  * @release - called when the property is removed from the device.  This is
 468  *            meant to allow a property to free its opaque upon device
 469  *            destruction.  This may be NULL.
 470  *
 471  * @opaque - an opaque pointer to pass to the callbacks for the property
 472  *
 473  * @errp - returns an error if this function fails
 474  */
 475 void qdev_property_add(DeviceState *dev, const char *name, const char *type,
 476                        DevicePropertyAccessor *get, DevicePropertyAccessor *set,
 477                        DevicePropertyRelease *release,
 478                        void *opaque, Error **errp);
 479
 480 /**
 481  * @qdev_property_get - reads a property from a device
 482  *
 483  * @dev - the device
 484  *
 485  * @v - the visitor that will receive the property value.  This should be an
 486  *      Output visitor and the data will be written with @name as the name.
 487  *
 488  * @name - the name of the property
 489  *
 490  * @errp - returns an error if this function fails
 491  */
 492 void qdev_property_get(DeviceState *dev, Visitor *v, const char *name,
 493                        Error **errp);
 494
 495 /**
 496  * @qdev_property_set - writes a property to a device
 497  *
 498  * @dev - the device
 499  *
 500  * @v - the visitor that will be used to write the property value.  This should
 501  *      be an Input visitor and the data will be first read with @name as the
 502  *      name and then written as the property value.
 503  *
 504  * @name - the name of the property
 505  *
 506  * @errp - returns an error if this function fails
 507  */
 508 void qdev_property_set(DeviceState *dev, Visitor *v, const char *name,
 509                        Error **errp);
 510
 511 /**
 512  * @qdev_property_get_type - returns the type of a property
 513  *
 514  * @dev - the device
 515  *
 516  * @name - the name of the property
 517  *
 518  * @errp - returns an error if this function fails
 519  *
 520  * Returns:
 521  *   The type name of the property.
 522  */
 523 const char *qdev_property_get_type(DeviceState *dev, const char *name,
 524                                    Error **errp);
 525
 526 /**
 527  * @qdev_property_add_static - add a @Property to a device referencing a
 528  * field in a struct.
 529  */
 530 void qdev_property_add_static(DeviceState *dev, Property *prop, Error **errp);
 531
 532 /**
 533  * @qdev_get_root - returns the root device of the composition tree
 534  *
 535  * Returns:
 536  *   The root of the composition tree.
 537  */
 538 DeviceState *qdev_get_root(void);
 539
 540 /**
 541  * @qdev_get_canonical_path - returns the canonical path for a device.  This
 542  * is the path within the composition tree starting from the root.
 543  *
 544  * Returns:
 545  *   The canonical path in the composition tree.
 546  */
 547 gchar *qdev_get_canonical_path(DeviceState *dev);
 548
 549 /**
 550  * @qdev_resolve_path - resolves a path returning a device
 551  *
 552  * There are two types of supported paths--absolute paths and partial paths.
 553  *
 554  * Absolute paths are derived from the root device and can follow child<> or
 555  * link<> properties.  Since they can follow link<> properties, they can be
 556  * arbitrarily long.  Absolute paths look like absolute filenames and are
 557  * prefixed with a leading slash.
 558  *
 559  * Partial paths look like relative filenames.  They do not begin with a
 560  * prefix.  The matching rules for partial paths are subtle but designed to make
 561  * specifying devices easy.  At each level of the composition tree, the partial
 562  * path is matched as an absolute path.  The first match is not returned.  At
 563  * least two matches are searched for.  A successful result is only returned if
 564  * only one match is founded.  If more than one match is found, a flag is
 565  * return to indicate that the match was ambiguous.
 566  *
 567  * @path - the path to resolve
 568  *
 569  * @ambiguous - returns true if the path resolution failed because of an
 570  *              ambiguous match
 571  *
 572  * Returns:
 573  *   The matched device or NULL on path lookup failure.
 574  */
 575 DeviceState *qdev_resolve_path(const char *path, bool *ambiguous);
 576
 577 /**
 578  * @qdev_property_add_child - Add a child property to a device
 579  *
 580  * Child properties form the composition tree.  All devices need to be a child
 581  * of another device.  Devices can only be a child of one device.
 582  *
 583  * There is no way for a child to determine what its parent is.  It is not
 584  * a bidirectional relationship.  This is by design.
 585  *
 586  * @dev - the device to add a property to
 587  *
 588  * @name - the name of the property
 589  *
 590  * @child - the child device
 591  *
 592  * @errp - if an error occurs, a pointer to an area to store the area
 593  */
 594 void qdev_property_add_child(DeviceState *dev, const char *name,
 595                              DeviceState *child, Error **errp);
 596
 597 /**
 598  * @qdev_property_add_link - Add a link property to a device
 599  *
 600  * Links establish relationships between devices.  Links are unidirectional
 601  * although two links can be combined to form a bidirectional relationship
 602  * between devices.
 603  *
 604  * Links form the graph in the device model.
 605  *
 606  * @dev - the device to add a property to
 607  *
 608  * @name - the name of the property
 609  *
 610  * @type - the qdev type of the link
 611  *
 612  * @child - a pointer to where the link device reference is stored
 613  *
 614  * @errp - if an error occurs, a pointer to an area to store the area
 615  */
 616 void qdev_property_add_link(DeviceState *dev, const char *name,
 617                             const char *type, DeviceState **child,
 618                             Error **errp);
 619
 620 /**
 621  * @qdev_property_add_str
 622  *
 623  * Add a string property using getters/setters.  This function will add a
 624  * property of type 'string'.
 625  *
 626  * @dev - the device to add a property to
 627  *
 628  * @name - the name of the property
 629  *
 630  * @get - the getter or NULL if the property is write-only.  This function must
 631  *        return a string to be freed by @g_free().
 632  *
 633  * @set - the setter or NULL if the property is read-only
 634  *
 635  * @errp - if an error occurs, a pointer to an area to store the error
 636  */
 637 void qdev_property_add_str(DeviceState *dev, const char *name,
 638                            char *(*get)(DeviceState *, Error **),
 639                            void (*set)(DeviceState *, const char *, Error **),
 640                            Error **errp);
 641
 642 /**
 643  * @qdev_get_type
 644  *
 645  * Returns the string representation of the type of this object.
 646  *
 647  * @dev - the device
 648  *
 649  * @errp - if an error occurs, a pointer to an area to store the error
 650  *
 651  * Returns: a string representing the type.  This must be freed by the caller
 652  *          with g_free().
 653  */
 654 char *qdev_get_type(DeviceState *dev, Error **errp);
 655
 656 /**
 657  * @qdev_machine_init
 658  *
 659  * Initialize platform devices before machine init.  This is a hack until full
 660  * support for composition is added.
 661  */
 662 void qdev_machine_init(void);
 663
 664 /**
 665  * @device_reset
 666  *
 667  * Reset a single device (by calling the reset method).
 668  */
 669 void device_reset(DeviceState *dev);
 670
 671 #endif